Control systems for internal combustion engines



P 1961 F, HENNINGER 3,001,516

CONTROL SYSTEMS FOR INTERNAL COMBUSTION ENGINES Filed Feb. 24, 1960 3 Sheets-Sheet 1 26 78c '32 26b 30a 30d 300 30c 30b Sept. 26, 1961 F. HENNINGER 3,001,516

CONTROL SYSTEMS FOR INTERNAL COMBUSTION ENGINES Filed Feb. 24, 1960 3 Sheets-Sheet 2 Sept. 26, 1961 F. HENNINGER 3,001,515

CONTROL SYSTEMS FOR INTERNAL COMBUSTION ENGINES Filed Feb. 24, 1960 3 Sheets-Sheet 3 I/ I C) PM 78b 51 10%,52

2155 26y 78c 3 C) HQ] lab} in a 52 /Iad Unitedv States Patent C) man company Filed Feb. 24, 1960, Ser. No. 10,777 Claims priority, application Germany Feb. 25, 1959 1 Claim.

The invention relates to control systems for reversible internal combustion engines and more particularly to such systems of the kind wherein a camshaft is brought by means of a double-acting shifting cylinder into two pos1tions corresponding to the directions of rotation for ahead and astcrn, said camshaft carrying with it a multiple cam incorporating two reversing cams which, on movement of the multiple cam from the operating to the reversing position, such movement being transverse to the direction of shift of the camshaft, open in each case an associated reversing valve, which supplies pressure medium to the shifting cylinder for shifting the camshaft from the particular position to the other end position. In such devices, the camshaft must be secured against longitudinal displacement in the end positions so that, under the influence of the valve-operating forces applied to its cams, it cannot be shifted from its operative position into an intermediate position prejudicial to operation. Normally, this blocking is effected by a springloaded pawl which on reversal, is disengaged either by the shifting force, which considerably exceeds the longitudinal forces set up by valve operation or by a special release device. In one case, considerable forces act on the pawl, which may produce wear and deformation, while in the other case an undesirable expenditure must be accepted.

It is the object of the invention to obviate the aforesaid disadvantages and to solve the problem of camshaft blocking with minimum expenditure. In a system of the kind hereinbefore mentioned, this problem is solved according to the invention by the fact that the multiple cam has blocking cams associated therewith adapted to co-operate one with each of the two reversing valves, each of said blocking cams in one of the two end positions of the camshaft, being nearest that reversing valve, the opening of which would allow the camshaft to remain in the operative position, so that in the event of undesired shifting of the camshaft from the operative position, that reversing valve which admits pressure medium to the shifting cylinder to effect return of the shaft to the operative position will be opened.

The particular advantage of this solution is that it obviates mechanical parts, which may be subject to strain and deformation for example in the case of leak-age of one of the reversing valves. In addition, the attendant has his attention drawn to disturbances in the camshaft position by the operating noises of the valves which occur in the event of the return operation.

According to another feature of the invention, the position of the blocking cams is advantageously so selected that the blocking cams can only co-operate with the re versing valves in the operative position of the multiple cam in the case of unwanted displacements of the camshaft, since in the starting position, the reversing cams assume the function of blocking.

A device according to the invention is represented diagrammatically in the drawing, wherein:

FIGURE 1 shows the overall circuit diagram of the reversing system, while FIGURE 2 shows a section through the shifting cylinder.

FIGURES 3 to 6 ShO'W developments of the multiple cam in the two operative positions and in the position reversing and starting astern.

The invention will be described hereinafter with reference to the example of a pneumatic remote-control installation for a reversible diesel engine for ship propulsion.

On the bridge or at an operating station situated at a point remote from the engine are a valve '1 for reversing and starting in the ahead direction of rotation, a valve 2 for reversing and starting in the astern" direction of rotation and a stop valve 3. As shown, the valves may be accommodated in a common housing 4, which comprises a chamber 5 supplied with compressed air. Each valve consists of a valve cone 1a, 2a, 3a, a pressure spring 1b, 2b and 3b, which holds the cone on its seat, a hollow push button 1c, 20, 3c and a spring 1d, 2d, 30?, which returns the push-button to [the resting position, in which the pipeline controlled by the respective valve is discharged.

All the other parts are built onto the engine itself.

. From the valve 1, a pipeline 6 leads to the space 7 of an operating cylinder -8, such cylinder housing a piston 9 which, when the spaces 7 and 12 at opposite sides thereof are discharged, is maintained in the central position shown by means of springs 10 and 11. The other space 12 of the cylinder 8 is connected by a pipeline 13 to the valve 2. Connected to the piston 9 is a piston rod 14, which carries a link block 15 engaged by a reversing lever 16 and which is guided by the guide 17. The lever 16 can assume the positions V (ahead) and Z (astern) as well as the central position shown. The lever 16 co-operates with a multiple cam 18 the an'angernent being such that while the cam is movable angularly with said lever it is nevertheless capable of an axial sliding movement. The cam 18 has individual cams 18a for reversal ahead, 18b for reversal astern, for starting ahead and 18d for starting astern. The cam 18 is rotatably mounted on an extension 19 of a camshaft 20, and is secured against longitudinal sliding relatively to said shaft by collars 21 and 22, so that it follows every longitudinal displacement of the camshaft 20 (see FIG- URE 2). The reversing lever 16 slides in a groove 23 in the multiple cam 18, so that it does not follow the longitudinal movement of the cam. The individual cam 18a, in the astern position of the camshaft 20, is adapted to co-operate with a reversing valve 24 for reversing ahead. The individual cam 18b, in the ahead position of the camshaft 20, is adapted to co-operate with a reversing valve 25 for reversing astern. The individual cam 180, in the ahead position of the camshaft 20, is adapted to co-operate with a starting valve 26. The individual cam 18d, in the astern position of the camshaft 20, is adapted to co-operate with a starting valve 26. The valves 24, 25, 26 comprise respectively valve cones 24a, 25a and 26a, as well as pressure springs 24b, 25b and 26b, which hold the valve cones on their seats. Leading to the valves 24 and 25 is a pipeline 28, which comes from a pressure-reducing valve 27 and in which a pressure of about 8 kg./cm. prevails. Leading to the valve 27 is a branch 22a from a high-pressure air pipeline 29, from which latter a branch 2% also leads to the valve 26 said pipeline 29 itself being connected to a main starting valve 30. The main starting valve 30 comprises a piston valve 30a comprising a valve cone 30c and a piston 302 and it will be seen that the pipeline 29 opens into a space 30b Which is also connected by a pipeline 31 to the starting valves, not shown, mounted on the engine cylinders. A pipeline 32, coming from the starting valve 26, opens into a space 30d within the starting valve. Leading from the valve 24 is a pipeline 33 having a branch 33a leading to an oil vessel 35a. Leading from the valve 25 is a pipeline 34 having a branch 34a leading to an oil vessel 35b. The oil vessels 35a, 35b are associated with the cylinder, hereinafter termed the shifting cylinder 35 and they are in communication with spaces 35c and 35d in front of and behind a piston 35e fixed to the camshaft extension 19. The camshaft extension 19 is connected to the camshaft 20 for rotation relatively thereto, but fast in the axial direction. From the pressure-reducing valve. 27 a pipeline 36 leads by way of a shut-off valve 37 to the chamber of the housing 4. A pipeline 38 leads from the stop valve 3 to a port 3912 of a double non-return valve 39, in which a valve piston 39a slides thereby to connect either the port 3922 or a port 39c to a port 39d. Branches 33b and 34b of the pipelines 33 and 34 are connected to ports 4G0 and 40b of a double non-return valve 40, in which a valve piston 40a slides thereby to connect either the port 40b or 400 to a port 40d. The port 40d is connected by a pipeline 41 to the port 39c of the double non-return valve 39. From the port 39d of the double non-return valve 39, a pipeline 4-2 leads to an operating cylinder 43, in which slides a piston 43a, which is urged into a rest position by a spring 43b. A piston rod 43c connected to the piston 43a is pivotally connected to a shut-off lever 44, to which is connected the regulating rod 45 of the injection pump, not shown. The shut-off lever 44 can assume the positions B (operation) and S (stop), in which it is capable of shifting the regulating rod 45 only in the shut-off direction, while in the opposite direction the said rod is left free to the influence of the speed governor, not shown.

The mode of operation of the device will be explained hereinafter with reference to a reversing operation.

In FIGURE 3, the camshaft 20 is shown in the ahead position. The position of the individual cams of the multiple cam can be seen clearly from the development. Here, as in the following figures, 50 denotes a blocking cam for ahead position while 51 denotes the blocking cam for astern position. If the camshaft 20 and with 'it the cam 18 were to shift undesirably in the direction of the camshaft axis 52 towards a stop 54, the blocking cam 50 would open the reversing valve 24 and cause admission of compressed air to the shifting cylinder 35, so that the camshaft 20 and the multiple cam 18 would be moved back towards a stop 53. Due to this movement, the blocking cam 50 would come out of engagement with the valve which would close again, thereby establishing the starting position. The stops 53 and 54 are illustrated schematically in FIGURES 3 to 6. They are in fact constituted by bosses. at opposite ends of the interior of the shifting cylinder 35 as shown in FIGURE 2.

If the push-button 2c is pressed, the space '12 of the operating cylinder 8 receives compressed air by way of the pipeline 13, and the lever 16 moves into position Z (FIGURE 1). The lever 16 can also be thrown over into this position by hand. The multiple cam 18 is thereby rotated in an anticlockwise direction, and the individual cam,18b opens the reversing valve 25, which gives admission to the oil vessel 35b byway of pipelines 34 and 34a. The corresponding position of the multiple cam 18 is shown in FIGURE 4. At the same time, compressed air passes through pipeline 34b to the poet 40b of the double non-return valve 40, presses the valve piston 40a on to the port 400, which releases the path for the compressed air to the poet 40d, the compressed air passing through the pipeline 41 to the port 39c of the double non-return valve 39, where it presses the valve piston 39a on to the port 3919, thus releasing the port 39d so that compressed air isadmitted by way of the pipeline 42 to the operating cylinder 43. By means of the piston rod 43b and the shut-off lever 44', the piston 43a moves the regulating rod 45 into the stop position, whereby the speed of the engine falls to about A of the maximum speed. In the meantime, the camshaft 20 has travelled to the left, the cam 18b shortly before reaching the left-hand end position has come out of engagement with the valve 25, while the individual cam- 18d. has opened the valve 26. This position of the multiple cam is shown in FIGURE 5. Due to the closing of valve 25, the operating cylinder 43 is discharged of air, and therefore the regulating rod 45 is left to the influence of the speed governor. Due to the opening of the valve 26, high-pressure compressed air passes to the main starting valve 3d and opens it, whereby the engine cylinders are supplied with compressed air. The engine is thereby retarded and started in the astern direction of rotation. If the push-button 2c or the lever 16 is released; the latter under the influence of the spring 11, or because the chamber 12' is discharged, returns to the central position. The cam 18d thereby comes out of engagement with the valve 26, the latter and the main starting valve 30 close, and the supply of starting air stops, so that the engine operates normally. This position isshown in FIGURE 6. It will readily be appreciated that the blocking cam 51 in co-operation wiht the reversing valve 25 in the position takes over the securing of the position of the camshaft 20 in the hereinbefore described manner.

I claim:

A power operator for connection to the cam shaft of an internal combustion engine, said cam shaft having first and second positions according to the directionof rotation of said engine, said power operator comprising a cylinder having ports in oppositeends thereof, a piston reciprocable in said cylinder, two separate reservoirs connected one to each of said ports for supplying an operating liquid to and for receiving return flow of liquid from said cylinder through said ports thereof, means forv supplying fluid pressure to said reservoirs, a multiple cam operationally coupled to said piston whereby reciprocation of the piston effects first and second displacements of the cam whilst simultaneously changing the position: of said control shaft as between said first and second positions, a plurality of cam surfaces formed on. said; multiple cam, selectively actuatable means coupled to said multiple cam for displacing said multiple-cam'by third and fourth displacements according to-the desired, direction of rotation of said engine, the directionof said. third and fourth displacements being perpendicular. to the direction of said first and second displacements, a first valve means actuatable by a first cam surface of said multiple cam upon said third displacement to "supply said fluid pressure to one of said reservoirs, a second, valve means actuatable by a second cam surface of. said multiple cam upon said fourth displacement to supply; fluid pressure to the other of said reservoirs, ,a first-blocking cam surface on said multiple camfor actuating said.

first valve means, a second blocking cam surface on-said multiple cam for actuating said second valve means,rsaid first andsecond blocking cam surfaces actuating said first.

and second valve means upon an undesired displacement. of said cam shaft out of said first and second positions in order to effect return of said shaftto the desiredpost 2,239,893 Jackman Apr. 29,- 19.41. 2,402,419

2,911,960 Benz Nov. 10, 1959 Larson June 18, 1946- .jam 

